Analytical and Numerical Evaluation of the Cyclic Yield Area Criteria for Shakedown Requirements

2002 ◽  
Author(s):  
Isoharu Nishiguchi ◽  
Asao Okamoto ◽  
Norimichi Yamashita ◽  
Mitsuru Aoki
Keyword(s):  
Pressure Vessel ◽  
Numerical Evaluation ◽  
Failure Modes ◽  
Three Dimensional ◽  
Fem Analysis ◽  
Stress Evaluation ◽  
Division 1 ◽  
Section Viii ◽  
Division 2 ◽  
Stress Criteria

The rules in codes such as the ASME Boiler and Pressure Vessel Code Section III Division 1 and Section VIII Division 2, provide the concept of stress categorization to prevent inelastic failure modes based on the elastic analyses. The categorization of the stresses obtained by the FEM analysis, however, is not always clear and the Three Dimensional FEM Stress Evaluation in JPVRC (TDF committee) has been developed alternative criteria to dispense with the stress categorization. As for the evaluation of the primary plus secondary stress, criteria based on the concept of the Cyclic Yield Area (CYA) have been developed. In this paper, the recent results obtained in the committee are summarized to evaluate the validity and the usability of the criteria.

A Study of the Conservatism in ASME BPVC Section VIII Division 2 Opening Design for External Pressure

2019 ◽  
Author(s):  
Barry Millet ◽  
Kaveh Ebrahimi ◽  
James Lu ◽  
Kenneth Kirkpatrick ◽  
Bryan Mosher
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Pressure Vessel ◽  
External Pressure ◽  
The Other ◽  
Finite Element Analyses ◽  
Division 1 ◽  
Section Viii ◽  
Allowable Compressive Stress ◽  
Division 2

Abstract In the ASME Boiler and Pressure Vessel Code, nozzle reinforcement rules for nozzles attached to shells under external pressure differ from the rules for internal pressure. ASME BPVC Section I, Section VIII Division 1 and Section VIII Division 2 (Pre-2007 Edition) reinforcement rules for external pressure are less stringent than those for internal pressure. The reinforcement rules for external pressure published since the 2007 Edition of ASME BPVC Section VIII Division 2 are more stringent than those for internal pressure. The previous rule only required reinforcement for external pressure to be one-half of the reinforcement required for internal pressure. In the current BPVC Code the required reinforcement is inversely proportional to the allowable compressive stress for the shell under external pressure. Therefore as the allowable drops, the required reinforcement increases. Understandably, the rules for external pressure differ in these two Divisions, but the amount of required reinforcement can be significantly larger. This paper will examine the possible conservatism in the current Division 2 rules as compared to the other Divisions of the BPVC Code and the EN 13445-3. The paper will review the background of each method and provide finite element analyses of several selected nozzles and geometries.

Heat Treatment of Fabricated Components and the Effect on Properties of Materials

2019 ◽  
Author(s):  
Shyam Gopalakrishnan ◽  
Ameya Mathkar
Keyword(s):  
Heat Treatment ◽  
Pressure Vessel ◽  
Test Specimen ◽  
Stress Relieving ◽  
Division 1 ◽  
Asme Code ◽  
Alloy Steels ◽  
Section Viii ◽  
Properties Of Materials ◽  
Division 2

Abstract Most of the heavy thickness boiler and pressure vessel components require heat treatment — in the form of post weld heat treatment (PWHT) and sometimes coupled with local PWHT. It is also a common practice to apply post heating/ intermediate stress relieving/ dehydrogenation heat treatment in case of alloy steels. The heat treatment applied during the various manufacturing stages of boiler and pressure vessel have varying effects on the type of material that is used in fabrication. It is essential to understand the effect of time and temperature on the properties (like tensile and yield strength/ impact/ hardness, etc.) of the materials that are used for fabrication. Considering the temperature gradients involved during the welding operation a thorough understanding of the time-temperature effect is essential. Heat treatments are generally done at varying time and temperatures depending on the governing thickness and the type of materials. The structural effects on the materials or the properties of the materials tends to vary based on the heat treatment. All boiler and pressure vessel Code require that the properties of the material should be intact and meet the minimum Code specification requirements after all the heat treatment operations are completed. ASME Code(s) like Sec I, Section VIII Division 1 and Division 2 and API recommended practices like API 934 calls for simulation heat treatment of test specimen of the material used in fabrication to ascertain whether the intended material used in construction meets the required properties after all heat treatment operations are completed. The work reported in this paper — “Heat treatment of fabricated components and the effect on properties of materials” is an attempt to review the heat treatment and the effect on the properties of materials that are commonly used in construction of boiler and pressure vessel. For this study, simulation heat treatment for PWHT of test specimen for CS/ LAS plate and forging material was carried out as specified in ASME Section VIII Div 1, Div 2 and API 934-C. The results of heat treatment on material properties are plotted and compared. In conclusion recommendations are made which purchaser/ manufacturer may consider for simulation heat treatment of test specimen.

Increased Allowable Stresses for Earthquake and Wind Loads in Section VIII, Division 1

1986 ◽  
Vol 108 (4) ◽  
pp. 518-520
Author(s):  
A. Selz
Keyword(s):  
Pressure Vessel ◽  
Wind Loads ◽  
Membrane Stress ◽  
Allowable Stresses ◽  
Division 1 ◽  
Section Viii ◽  
The Subject ◽  
Short Time ◽  
Creep Regime ◽  
Division 2

There has been a need for some time to provide rules for allowable stresses for short-time and infrequent loading such as earthquake and wind loads in Section VIII, Division 1 of the Boiler and Pressure Vessel Code. Such rules exist in Section VIII, Division 2, in Section III, and in many other Codes. Division 1 has been silent on the subject. This has caused some manufacturers to make their own rules, and some to overdesign their hardware. Neither situation is without problems. Therefore, in 1979 the Boiler and Pressure Vessel Committee undertook to develop rules for Section VIII, Division 1. This work resulted in the addition of paragraph UG-23(d) to the Code, in the Summer, 1983 Addenda. The paragraph permits an increase in general primary membrane stress of 20 percent for earthquake and wind loads for temperatures below the creep regime.

Review of Section VIII, Division 1 and 2 Changes, 2008–2010

2010 ◽  
Author(s):  
Thomas P. Pastor
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Major Event ◽  
The Past ◽  
Division 1 ◽  
Section Viii ◽  
Division 2

Three years ago the major event within Section VIII was the publication of the new Section VIII, Division 2. The development of the new VIII-2 standard dominated Section VIII activity for many years, and a new standard has been well received within the industry. As expected with any new standard, some of the material that was intended to be published in the standard was not ready at the time of publication so numerous revisions have taken place in the last two addenda. This paper will attempt to summarize the major revisions that have taken place in VIII-2 and VIII-1, including a detailed overview of the new Part UIG “Requirements for Pressure Vessels Constructed of Impregnated Graphite”. I have stated in the past that the ASME Boiler and Pressure Vessel Code is a “living and breathing document”, and considering that over 320 revisions were made to VIII-1 and VIII-2 in the past three years, I think I can safely say that the standard is alive and well.

Three-Dimensional Stress Criteria—Summary of the PVRC Project

1999 ◽  
Vol 122 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Greg Hollinger ◽  
John Hechmer
Keyword(s):  
Finite Element ◽  
Pressure Vessel ◽  
Research Council ◽  
Failure Modes ◽  
Three Dimensional ◽  
Analytical Techniques ◽  
Element Analysis ◽  
Elastic Stresses ◽  
Work Done ◽  
Stress Criteria

This paper summarizes work done by the Pressure Vessel Research Council (PVRC) on three-dimensional stress criteria, using primarily elastic two and three-dimensional analytical techniques, finite element analysis. The focus of the work was to recommend guidelines on evaluation of elastic stresses relative to the ASME Boiler and Pressure Vessel Code (Code) defined failure modes as they relate to stress limits. The guidelines are developed such that they may be used to update and expand the procedures for evaluating the required stress limits in Code Section VIII, Division 2 and Code Section III, Subsection NB. This paper summarizes the recommendation using ten guidelines. The project addresses eleven example problems, nine of which include finite element analyses. These example problems validate the recommendations. The detailed information is published in the Welding Research Council Bulletin 429, “3-D Stress Criteria Guidelines for Applications.” [S0094-9930(00)01601-2]

ASME B&PV Code Section VIII Pressure Vessel Design: A Comparison — Division 1 Versus Division 2

2002 ◽  
Author(s):  
Dwight V. Smith
Keyword(s):  
Pressure Vessel ◽  
Pressure Vessels ◽  
Main Design ◽  
Division 1 ◽  
Asme Code ◽  
Section Viii ◽  
Design Requirements ◽  
Division 2

Historically, the ASME B&PV Code, Section VIII, Division 2, Alternative Rules for Construction of Pressure Vessels (Div.2), ASME [1], was usually considered applicable only for large, thick walled pressure vessels. Otherwise, ASME B&PV Code, Section VIII, Division 1, Rules for Construction of Pressure Vessels (Div. 1), ASME [2], was typically applied. A case can also be made for the application of the Div. 2 Code Section for some vessels of lesser thicknesses. Each vessel should be closely evaluated to ensure the appropriate choice of Code Section to apply. This paper discusses some of the differences between the Div. 1 and Div. 2 Code Sections, summarizes some of the main design requirements of Div. 2, and presents a ease for considering its use for design conditions not usually considered by some, to be appropriate for the application of Div. 2 of the ASME Code.

An Overview of the New ASME Section VIII, Division 2 Pressure Vessel Code

2003 ◽  
Author(s):  
David A. Osage
Keyword(s):  
Pressure Vessel ◽  
Major Revision ◽  
Division 1 ◽  
Efficient Construction ◽  
Section Viii ◽  
Division 2

ASME has decided to undertake a major revision, including significant technical updates, of Section VIII, Division 2 of the Boiler and Pressure Vessel Code. Division 1 will not be affected, but it is anticipated that the revised Division 2 Code will allow significantly more efficient construction for many current Division 1 applications. As a result, it is expected that the revised code will be used for many more applications than the current Division 2.

Technical Basis for Code Cases on Design of Ellipsoidal and Torispherical Heads for ASME Section VIII Vessels

1999 ◽  
Vol 122 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Mahendra D. Rana ◽  
Arturs Kalnins
Keyword(s):  
Failure Modes ◽  
Low Cycle Fatigue ◽  
Plastic Collapse ◽  
Cycle Fatigue ◽  
Dimensional Changes ◽  
Division 1 ◽  
Section Viii ◽  
Technical Basis ◽  
Division 2 ◽  
Fatigue Criterion

ASME Boiler and Pressure Vessel (B&PV) Code Committees have approved Code Cases 2260 and 2261 on the design of ellipsoidal and torispherical heads for Section VIII Division 1 and Division 2 vessels, respectively. Burst and low-cycle fatigue failure modes have been considered. A rationale is provided for including the foregoing referenced failure modes, and not including other failure modes such as dimensional changes, plastic collapse, knuckle yielding, etc. The basis for the specified design formulas to satisfy the burst and low-cycle fatigue criterion is discussed. The paper also discusses limitations and other requirements that have been imposed in the Code Cases. [S0094-9930(00)01401-3]

Applicability of Design Rules for Openings in Shells, ASME B&PV Code, Section VIII, Division 2 - A Case Study

2021 ◽  
Author(s):  
Gurumurthy Kagita ◽  
Krishnakant V. Pudipeddi ◽  
Subramanyam V. R. Sripada
Keyword(s):  
Stress Analysis ◽  
Failure Modes ◽  
Element Analysis ◽  
Design Rules ◽  
Area Method ◽  
Replacement Method ◽  
Local Stresses ◽  
Pressure Area ◽  
Section Viii ◽  
Division 2

Abstract The Pressure-Area method is recently introduced in the ASME Boiler and Pressure Vessel (B&PV) Code, Section VIII, Division 2 to reduce the excessive conservatism of the traditional area-replacement method. The Pressure-Area method is based on ensuring that the resistive internal force provided by the material is greater than or equal to the reactive load from the applied internal pressure. A comparative study is undertaken to study the applicability of design rules for certain nozzles in shells using finite element analysis (FEA). From the results of linear elastic FEA, it is found that in some cases the local stresses at the nozzle to shell junctions exceed the allowable stress limits even though the code requirements of Pressure-Area method are met. It is also found that there is reduction in local stresses when the requirement of nozzle to shell thickness ratio is maintained as per EN 13445 Part 3. The study also suggests that the reinforcement of nozzles satisfy the requirements of elastic-plastic stress analysis procedures even though it fails to satisfy the requirements of elastic stress analysis procedures. However, the reinforcement should be chosen judiciously to reduce the local stresses at the nozzle to shell junction and to satisfy other governing failure modes such as fatigue.

Design, Manufacture and Safety Aspects of Forged Vessels for High-Pressure Services

1980 ◽  
Vol 102 (1) ◽  
pp. 98-106 ◽  
Author(s):  
G. J. Mraz ◽  
E. G. Nisbett
Keyword(s):  
High Pressure ◽  
Pressure Vessel ◽  
Low Alloy Steels ◽  
Nickel Chromium ◽  
Molybdenum Alloys ◽  
Tension Tests ◽  
Alloy Steels ◽  
Section Viii ◽  
Division 2

Steels at present included in Sections III and VIII of the ASME Boiler and Pressure Vessel Code severely limit its application for high-pressure design. An extension of the well-known AISI 4300 series low alloy steels has long been known as “Gun Steel.” These alloys, which are generally superior to AISI 4340, offer good harden-ability and toughness and have been widely used under proprietary names for pressure vessel application. The ASTM Specification A-723 was developed to cover these nickel-chromium-molybdenum alloys for pressure vessel use, and is being adopted by Section II of the ASME Boiler and Pressure Vessel Code for use in Section VIII, Division 2, and in Section III in Part NF for component supports. The rationale of the specification is discussed, and examples of the mechanical properties obtained from forgings manufactured to the specification are given. These include the results of both room and elevated temperature tension tests and Charpy V notch impact tests. New areas of applicability of the Code to forged vessels for high-pressure service using these materials are discussed. Problems of safety in operation of monobloc vessels are mentioned. Procedures for in-service inspection and determination of inspection intervals based on fracture mechanics are suggested.

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